North Dakota Water Science Center
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The Red River of the North (Red River) begins at Wahpeton at the confluence of the Otter Tail River, which originates in east-central Minnesota, and the Bois de Sioux River, which originates in northeastern South Dakota. The Red River forms the boundary between North Dakota and Minnesota and flows north into Canada, meandering for 394 miles, which is nearly double the straight-line distance.
A question commonly asked about the Red River is, "Why does it flow north?". The answer is: Lake Agassiz, a lake formed by melting glaciers, covered much of what is today western Minnesota, eastern North Dakota, southern Manitoba, and southwestern Ontario from about 12,500 years ago to about 7,500 years ago. Lake Agassiz virtually disappeared, leaving a few remnants such as Minnesota's Upper and Lower Red Lakes and Lake of the Woods and Canada's Lake Winnipeg, Lake Manitoba, and Lake Winnipegosis. Lake Agassiz also left a fertile, flat plain that drains to the north, ultimately to Hudson Bay. The Red River flows north through this plain to Lake Winnipeg because, despite the plain being very flat, a difference in elevation exists along the route of the river, making the line between southeastern North Dakota and Lake Winnipeg slightly downhill. At the confluence of the Bois de Sioux and Otter Tail Rivers near Wahpeton, where the Red River begins, the elevation is 943 feet above mean sea level. The elevation of Lake Winnipeg is 714 feet above mean sea level.
In addition to being located in a flat plain, the Red River also has a shallow river channel. Because of the northerly flow of the river, the flatness of the Red River Basin, and the shallow river channel, the timing of spring thaw and snowmelt can greatly aggravate flooding. Snow in the upper part of the Red River Basin begins to melt first, when areas downstream remain largely frozen. This melt pattern can cause ice jams to form, and subsequent backwater (water that is retarded, backed up, or turned back in its course because of an obstruction or an opposing current) can occur as flow moves north toward the ice jams and frozen river-channel ice.
Red River Resources
Below are images of scenery along the Red River. Click on an image to view a larger version. Use your browser's back command to return to this page.